如何在woocommerce中增加/减少产品数量时从商店页面更新购物车？

add_action('wp_enqueue_scripts', 'custom_ajax_scripts');
function custom_ajax_scripts() {
    wp_enqueue_script('custom-ajax-script', get_stylesheet_directory_uri() . '/js/custom-ajax.js', array('jquery'), '1.0', true);
    wp_localize_script('custom-ajax-script', 'custom_ajax_object', array('ajax_url' => admin_url('admin-ajax.php')));
}

jQuery(document).ready(function($) {
    $('.quantity').on('click', '.plus, .minus', function() {
        var $quantityInput = $(this).closest('.quantity').find('input.qty');
        var currentVal = parseFloat($quantityInput.val());
        var maxVal = parseFloat($quantityInput.attr('max'));
        var minVal = parseFloat($quantityInput.attr('min'));
        var step = parseFloat($quantityInput.attr('step'));

        if ($(this).is('.plus')) {
            if (maxVal && (currentVal >= maxVal)) {
                $quantityInput.val(maxVal);
            } else {
                $quantityInput.val(currentVal + step);
            }
        } else {
            if (minVal && (currentVal <= minVal)) {
                $quantityInput.val(minVal);
            } else if (currentVal > 0) {
                $quantityInput.val(currentVal - step);
            }
        }

        $quantityInput.trigger('change');
        return false;
    });
});

add_action('wp_ajax_update_cart', 'custom_update_cart');
add_action('wp_ajax_nopriv_update_cart', 'custom_update_cart');
function custom_update_cart() {
    if (isset($_POST['product_id'], $_POST['quantity'])) {
        $product_id = absint($_POST['product_id']);
        $quantity = wc_stock_amount($_POST['quantity']);
        WC()->cart->set_quantity($product_id, $quantity, true);
        WC()->cart->calculate_totals();
        WC_AJAX::get_refreshed_fragments();
    }
    die();
}

<input type="number" class="input-text qty text" step="1" min="0" max="" name="quantity" value="1" title="Qty" size="4" pattern="[0-9]*" inputmode="numeric">